Echoing something I learnt recently, that secondary action works best through free body parts, this research taught me that extremities cause leakage of emotions through fidgeting. This offers a psychological justification that can be extrapolated into animation.
I also learnt about some body language poses that could help with setting up key poses.

- Floor Thing.

I learnt that having a backstory for the characters helps when you're trying to emulate character personalities. This even applies to the shortest short piece of animation. This is something Ed Hooks talks about - why a character goes into a room and where they are going affects how they will do it.

Camera angles affect what is primary and secondary action. Later I would realise this is significant - if I bring something that might be secondary action into the focus of the scene, does it remain secondary action? What happens to primary action? Do the same definitions apply?

Types of secondary action - conscious, unconscious, mannerisms. This is also an early hint into the spectral model of primary-secondary action. Is a mannerism a secondary action? Normally you'd say yes, but if I follow up by saying 'how important is how a character performs an action in terms of story?' You'd have to say very - it is very important to convey what a character's personality is.

This animation worked to support storytelling pose. Using silhouetting helped me make this animation easier to read, which is something you need in order for any subtext to be clear.

- Captain Nemo.

Silhouetting strengthens poses which strengthen narrative readability. This is a valuable technique.

With this animation I began to learn to put through a personality of a character through a combination of primary and secondary action.

- Gravity Cube.

Demonstrating ability to represent weight and friction in a digital medium.
Not massively significant in itself but it did point me in them direction of weight.

- Mime.

There are many parallels to be drawn between mime and animation.
Both revolve around imagining things that aren't there.
This book taught me things I knew already - emotive, storytelling poses are important for the audience to grasp what you're trying to show them. Strong key poses are very effective.
It gave me some ideas for a couple of new artefacts, including Pot On Head.

Pot On Head.

This was an exercise on weight. The character carrying the weight was the point of the scene.
I learned that there is room for secondary action in any type of scene, even one that's relatively mundane like this.
Primary action alone can produce a realistic character but adding in some secondary action, which communicates personality (subtext) results in a more human performance.

- Goon Takes a Drink.

I intended to go all out with this project but it didn't get very far.
I learnt that constraints are a bastard.

- Pot on Head with trip.

Whilst this works, to appeal more to the audience I should try to make a larger performance. Also, I should be conscious of the illusion of weight, not to break it.

This lead me onto Atlas, which was more or less a scaled up version of Pot on Head.

The comparison between the two actually suggests that subtext is altered by action. I think if I hid the objects on both characters, whilst the action is similar, it is clear they are handling different things. This shows how important mannerism is, how even though it is something you would call secondary action it is integral to the story.

- Atlas.

Atlas is still essentially a weight exercise, but I was able to squeeze in some secondary action in there that does thicken the subtext somewhat.

Atlas taught me something that today I realised I read in different words in John Borg's book. Secondary action can be better applied to parts of the body not engaged in an action.

I've also learnt to think of action as being on a scale of relevance to the story line.
An ultimate truth about life that I recognise is that the key is in the detail.
Although I overlook this sometimes, it always comes back. Once again it applies, to this.
Straight up primary action is good, and you get a story from it but you only get a good, complete story when you start adding in details. These might be objects, subplots and backstories. In the case of the latter two, you need extra detail in the acting to convey these. Secondary action is a detail that can't be omitted.

So where is this research leading me?

I have learnt that it isn't accurate to handle primary and secondary action discretely. The purpose of the scene is more important.
In the case of Atlas, the walking and carrying is most important. However, swearing under his breath, whilst less important, is still necessary for the story - otherwise you can't understand the fact he is annoyed, which would also essentially be the purpose of the scene. The way he struggles between each step is important to show that he finds the job hard, and offers a source for the annoyment.
The point is that if you get a character to do it, it is always for a reason. Thus, there are narrative implications. Without it, it changes the narrative. If you need it, it is key.

What will I do next, then?

A good demonstration of this is to make a piece of animation that has back story, subtext that I can communicate.